The use of network communication media such as wires, twisted pair cables and fiber optics has long been known in the art. Presently, such media are in widespread use in establishing links among many types of networked devices in which two or more such devices are in need of communication with one another. As a result, such media allow for realization of sophisticated networked systems in which each member can communicate with other members and other devices linked to the network.
Such media have been developed in a wide variety of electro-optical manufacturing and conduit design configurations, depending upon the intended need at the implementation site. One form of network communication medium in use today is known as a powered network communication medium. A powered network communication medium is generally comprised of a traditional underlying communication medium, such as a 10BaseT, 100BaseTx or a 1000 Base T Ethernet connection pair for transmitting data signals usually in the form of an AC-signal, but in which a power signal is also supplied. The power signal is used to supply “phantom” power to the network devices which receive and/or transmit the data signal. In this way, the network device can be supplied with both the operational power and the data via a single transmission media such as a cable. One example of use of such a powered network communication medium is in the field of internet phones in which power may be supplied to the internet phone via an internet transmission medium such as an Ethernet cable. As with traditional telephones, this approach practically eliminates the need for a second cable supplying power to each phone.
While used in the art, the foregoing powered approach for supplying power across a network transmission medium is not without shortcomings. In powered networking, it is essential that the supplied power (usually a direct current (DC) signal) does not adversely interfere with the integrity of the transmitted data (a differential alternating current (AC) signal). Unfortunately, factors such as a magnetic saturation of the transmission medium due to unbalanced DC resistance may create interference with the AC-data-signal which may result in disruptions and corruption of the data carried by the AC-signal. In addition, the DC-interference is only one of numerous factors, such as bad connectors or cable, faulty components, software errors, and the like, that can result in degradation of the AC-signal, thus making it exceedingly difficult to identify the DC-current as the source of the disruption of the AC-signal.
It is therefore highly desirable to be able to correctly attribute a given AC-signal disruption to the supplied DC-current for conducting efficient diagnosis and subsequent repair. This however, has proven to be an ongoing challenge since no known method currently exists to efficiently and correctly check for factors such as saturation of the magnetic elements in powered networking systems so that repairs can be quickly focused in that direction.
The present invention introduces a novel detection technique to efficiently and correctly detect disruptions of AC-signals caused by the supplied DC-current in a DC-type phantom-powered networking system.